Data processing system

ABSTRACT

A data processing system in which an arithmetic operation and the setting of a decimal point are carried out by a command entered from entry digit keys to thereby facilitate the setting of the specified decimal point and the starting of computation and make a contribution to the provision of a simplified device of small size.

United States Patent Inventors Yoshialii Suzuki [50 Fieldolsenl'ci 340/1715;

Tokyo; 235/IS7. I59, 160 Toshiharu lnamoto, Yokohama, both of, Japan [56] References Clted Appl. No. 798,342 UNITED STATES PATENTS 5"? d igf: 3,358,125 12/1967 Rinaldi......................... 235/l60X a C 3,375,356 3 1968 Se 'tt t 235 160 Assign" Elem 3 391 391 711968 Moll 72.5

Osaka, Japan Priority Feb. 28, 1968, June 4, was Prwwy Emmy-Paul J Hem Jam Am'smnr Examiner-R. F. Chapuran 43/132 and 43/4737 Attorney-Stevens, Davis, Miller and Mooher gg g g SYSTEM ABSTRACT: A data processing system in which an arithmetic I operation and the setting of a decimal point are carried out by [1.8. CI 340/1725, a command entered from entry digit keys to thereby facilitate 235/160 the setting of the specified decimal point and the starting of Int. G06! 3/00, computation and make a contribution to the provision of a G06f 7/38 simplified device of small aiu.

sw/rcH F cou/v TER {9-1 0 FLOP I9 /8 F i I REGISTER 20 g Y REGISTER /3 DISPLAY REsEr KEY PATENIED m2 5 [971 FIG. 3

SHEET 2 0F 2 F /6f 4 PUSH 26 Burrow 25 .1. RESET 1 24- KEY ARITHMET/C 22 m m/arm: f POWER CIRCUIT SW/TCH DISPLAY I COUNTER. 23

4 .w v. ON 22 OFF INVENTORS gosh/am .ruzuurl mswmnnw zwnuoro ATTORNEYS DATA PROCESSING SYSTEM The present invention relates to a data processing system and more particularly to improvements in a desk top electronic computer wherein the setting of a decimal point to be set and the starting of calculation are facilitated and the provision of a simplified construction is made so that a data processing system smaller in size than the conventional one may be obtained.

A conventional system of this type has been as illustrated in the schematic block diagram of FIG. 1, which comprises entry digit keys I representing decimal digits 0, l. 9, an arithmetic operation circuit 4 including arithmetic digit re gisters 2 and 3, a display means 5, and a switching means 6 with n contacts for setting the decimal point of data to be processed, whereby the result of the arithmetic operation performed by the logic operation circuit 4 is displayed on the display means in such condition that a specified decimal point is predetermined by the switching means 6 and simultaneously a given decimal point is displayed.

The prior system of such type, however, has been required to be provided with switch 6 having n contacts upon setting a decimal point and therefore, not only a large space was required for containing the switch but also there was the possibility of trouble occurring due to a failure of a multiplicity of contacts provided in the contact switch. Furthermore, in such a system in addition to an arithmetic operation a manual operation for setting a decimal point must be carried out by the switch 6 every time as required and therefore, it causes inconvenience to the user.

An object of the present invention, accordingly, is to provide a desk top electronic computer of small size in which such defects are obviated, capable of easily carrying out the setting of a decimal point.

Another object of the invention is to provide an improved and simplified desk top electronic computer of small size in which the size thereof can be reduced.

Other objects, features and advantages of the present invention will be better understood when reading the following detailed description in conjunction with the accompanying drawings, in which:

FIG. I is a schematic block diagram of an essential part of the conventional desk top electronic computer of small size;

FIG. 2 is a schematic block diagram of an essential part of a desk top electronic computer of small size in accordance with an embodiment of the present invention;

FIG. 3 is a diagram of various waveforms in time relationship for illustrating the operation of the device shown in FIG.

FIG. 4 is a schematic block diagram of a desk top electronic computer of small size in accordance with another embodiment of the present invention; and

FIG. 5 is a diagram of various waveforms in time relationship for illustrating the operation of an essential part of the system shown in FIG. 4.

Description of an embodiment of the present invention will be made by referring to FIGS. 2 and 3 hereinunder.

Referring to FIG. 2, numeral II designates entry digit keys, I2 and I3 respective registers, 14 an arithmetic operation circuit, and IS a display device. Numeral I6 designates an on-off switch for setting a decimal point. Flip-flop circuit 17 is provided which is set by means of switch 16 and reset by a data signal delivered from a reset terminal 18. Numerals I9 and designate an AND circuit and an INHIBIT circuit, respective ly. Gate circuits I9 and 20 are connected to the output of the flip-flop I7, and in the set state of the flip-flop I7 the gate circuit I9 is turned on and the gate circuit 20 is turned off by ap plication of an output signal from the digit keys II. Decimal point setting counter 21 counts the input signal delivered from the gate circuit 19, and its output is applied to the display device 15.

Now, the operation of the data processing system will be described with reference to the diagram in time relationship shown in FIG. 3.

First, the switch 16 is normally turned off and therefore, the flip-flop 17 is in its reset state, that is, it is held in its off state. Accordingly, data in the off state of the flip-flop contents entered from the digit keys are applied to the arithmetic operation circuit I4 since the gate circuit 20, is enabled, thus performing a normal operation. Now assume that it is desired to set a decimal point, when the switch I6 is actuated to energize the flip-flop I7 as shown by the waveform (a) in FIG. 3 the flip-flop I7 is driven in its set state as shown by the waveform (b) in FIG. 3, whereby the gate circuit I9 is turned on. In this state, it should be noted that if the digit keys II are depressed so that the decimal location may be set as desired, the content equal to that of the depressed digit key is applied to the counter 2I through the gate circuit I9 as shown by the waveform (c) in FIG. 3 and is then stored therein. On the other hand, when a reset signal as shown by the waveform (d) in FIG. 3 is applied to the reset terminal I8 at the completion of depressing the digit keys", the flip-flop is reset at that time, and accordingly, the gate circuit I9 is disabled, while the gate circuit 20 is enabled.

Now, when a signal to be operated as shown by the waveform (e) in FIG. 3 is applied to the arithmetic operation circuit 14 through the gate circuit 20 by depressing the digit keys I], an arithmetic operation is carried out therein, and the result of the operation is displayed on the display device 15, and concurrently the decimal location may be indicated on the display device on the basis of the information stored in the counter. Then, when a they are cleared, so that the contents registered in the operation circuit and the counter are erased therefrom operation circuit 14 and the display device IS by means of the reset key 22, the operated contents held therein are cleared.

In the above embodiment though a type is described wherein the reset key is provided in an independent form, it will be appreciated that the reset key may be provided as shown in FIG. 4.

Referring to FIG. 4, another embodiment of the present invention will be further described, wherein numerals 21 and 22 and numerals I4 and I5 correspond to the counter 2|, the reset key 22, the arithmetic operation circuit I4, ahd the display circuit IS of FIG. 2 respectively, terminal 29 corresponds to the output of the gate circuit I9 of FIG. 2 to which an input signal for setting the decimal location as required is applied, a switching lever 24 of a power switch 23 is provided with a contact 25 by which when a pushbutton switch 26 is pushed in the direction of the power switch 23 for making it turn on, the reset key or the reset circuit 22 is operated for a given period of time.

In accordance with such construction of the system the power switch 23 is turned on and at the same time the counter 21 and the arithmetic operation circuit can also be reset to clear the previous operation contents.

Referring to FIG. 5 there may be seen a waveform chart showing the operation of the above-mentioned system.

In this case, the system may be so arranged that the content entered into the counter 2I can be set in a predetermined set value without being reset in its zero state when the reset key 22 is actuated. Accordingly, since one pushbutton switch 26 for the power switch 23 can also serve for resetting the arithmetic operation circuit I4 as well as the counter 21, not only the manual operation of the system is very much facilitated, but also the size of the system can be reduced.

As described above, in accordance with the present invention, instead of a computer on the operation table of which there are usually arranged four means comprising a decimal point setting means, an arithmetic operation means, a reset means and a power switch control means, a minimum of two operation means are only to be provided due to the fact that the decimal point setting means and the logic operation, the reset means and the power switch control means are combined in construction, respectively.

There has accordingly been described herein a novel, useful, simple system according to this invention which has such advantages that the manual operation of the system is made easy, the construction thereof is simplified to render it small in size and the reset operation and the setting of a decimal point can quickly be carried out.

We claim:

1. In a desk top electronic computer having a set of entry digit keys, an arithmetic operation circuit performing an arithmetic operation in accordance with contents entered from said digit keys, a decimal location setting counter, display means for displaying the contents of said operation circuit and the decimal location stored in said counter, and reset means resetting said operation circuit and said display device, the improvement comprising means storing a decimal location setting in said counter, including means interrupting a signal from said entry keys to said arithmetic operation circuit, said interrupting means including gate circuits disposed between said keys and said operation circuit and said counter, respectively.

2. The device according to claim 1, wherein said storing means includes a flip-flop circuit operative with the action of an on-ofi' switch, an AND circuit having input terminals connected with the outputs of said keys and said flip-flop circuit, respectively, and having an output terminal connected to the input of said counter, and an INHIBIT circuit having input terminals connected in parallel with said input terminals of said AND circuit and having an output terminal connected to the input of said arithmetic operation circuit. said INHIBIT circuit being enabled where said flip flop is disabled.

3. The device according to claim I, wherein said reset means cooperates with an on-off switch of power supply means energizing said counter and said operation circuit for a predetermined period of time.

4. The device according to claim I, further comprising means resetting said counter by the actuation of said reset means when said counter contains a decimal location setting. 

1. In a desk top electronic computer having a set of entry digit keys, an arithmetic operation circuit performing an arithmetic operation in accordance with contents entered from said digit keys, a decimal location setting counter, display means for displaying the contents of said operation circuit and the decimal location stored in said counter, and reset means resetting said operation circuit and said display device, the improvement comprising means storing a decimal location setting in said counter, including means interrupting a signal from said entry keys to said arithmetic operation circuit, said interrupting means including gate circuits disposed between said keys and said operation circuit and said counter, respectively.
 2. The device according to claim 1, wherein said storing means includes a flip-flop circuit operative with the action of an on-off switch, an AND circuit having input terminals connected with the outputs of said keys and said flip-flop circuit, respectively, and having an output terminal connected to the input of said counter, and an INHIBIT circuit having input terminals connected in parallel with said input terminals of said AND circuit and having an output terminal connected to the input of said arithmetic operation circuit, said INHIBIT circuit being enabled where said flip-flop is disabled.
 3. The device according to claim 1, wherein said reset means cooperates with an on-off switch of power supply means energizing said counter and said operation circuit for a predetermined period of time.
 4. The device according to claim 1, further comprising means resetting said counter by the actuation of said reset means when said counter contains a decimal location setting. 